Actually, based on the point that you requested "non-smoker" but they smoke is sufficient enough to not rent it out. My gut feeling and previous experience renting out 4 bedrooms in our house for over 20 years proved to have more negative experience than positive. All of which appeared very nice and innocent too (at first). There could be exceptions. Just remember that it is your home and you are liable of which deposits can't even cover some of your losses you may experience. I know it sounds cruel but you have to protect the interest of yourself and your family. If anything happens, your tenants lose deposit and say bye-bye (that's actually a better situation than what we've seen and experienced) but your losses may not even begin to cover what you've made as rent. Judging from the lying and uncertainty with the income, etc. I won't expect too much from them. Hopefully, it's an exception for you. Good luck!